3-substituted BINOL Ligands. Synthesis And Application In Asymmetric Catalysis

Chiral BINOL is an important chiral axial compound which wa s one of the most important chiral reagents and widely used in vari ous kinds of asymmetric catalysis reactions for its strong structure s t-ability, the high chiral recognition ability and quality. By now, a1arge number of3,3’and6,6’di-substituted BINOLS (C2symmetry) have been reported among the binaphthol derivatives. However, ther e is few reports on3-monosubstituted BINOL Ligands(Cl symmetr y).Introduce the aliphatic hydroxymethyl, dimethylhydroxymethyl, diethylhydroxymethyl and aromatic diphenylhydroxymethyl3,3,5,5’-tetra(trifluoromethyl)diphenylhydroxymethyl on the troisime-positon of BINOL. Six ligands with different and steric effects have been s ynthesized systematically. Based on this, these ligands have been us-ed in recognizing asymmetric catalysis and some certain achieveme nts have been obtained in the preliminary tentative reaction.Ligands coordinate with Fe3+、 La3+、Al3+have been used to cat alyze the epoxidtion of α,β-Unsaturated ketone. As a result, high yi eld but poor enantiomeric selectivity was obtained when the ligands were coordinated with Fe3+or Al3+. While in the presence of La3+, not only high yield, but also45.27%of ee was achieved. Besides t hat the asymmetric addition of alkynylzinc to unsaturated aldehydes catalyzed with our synthesized ligands were also checked:26-43%of ee values were abtained when Ligand la,2a or3a was used asc atalyst.All the ligands and epoxide have been confirmed by1H-NMR,13C-NMR and MS.